Method and apparatus for indicating a temporary block flow to which a piggybacked ACK/NACK field is addressed

Abstract

A method and an apparatus for indicating a temporary block flow (TBF) to which a piggybacked acknowledgement/non-acknowledgement (PAN) field is addressed. A method and apparatus of performing receive processing to reduce the probability of false acceptance of erroneous PANs are also disclosed. A transmit station generates a PAN check sequence (PCS) and performs a channel coding on a PAN field and the PCS. The transmit station scrambles the encoded bits of the PAN field and the PCS with a TBF-specific scrambling code. Because of the scrambling, the PCS decoding at a receive station will pass if the data block is received by an intended receive station, while the PCS decoding will fail if received by a non-intended receive station. Alternatively, the scrambling may be performed before the channel coding. Alternatively, the transmit station may combine the PAN field and a temporary flow identity (TFI) to generate a PCS.

What is claimed is: 
     
       1. A method for processing a piggybacked acknowledgement/non-acknowledgement (PAN) field included in a data block to indicate an acknowledgement (ACK) or a non-acknowledgement (NACK) for a particular temporary block flow (TBF), the TBF being a temporal connection between a mobile station and a network to support a uni-directional transfer of data, the method comprising:
 receiving a data block including coded bits of a PAN field and a PAN check sequence (PCS); 
 decoding the coded bits of the PAN field and the PCS; 
 evaluating a channel link quality based on a soft metric computed during the decoding of the coded bits of the PAN field and the PCS; and 
 accepting the PAN field and the PCS based on evaluation of the channel link quality. 
 
     
     
       2. The method of  claim 1  wherein the channel link quality is evaluated by comparing a soft metric computed during the decoding of the coded bits with a threshold. 
     
     
       3. The method of  claim 1  wherein the soft metric is a best survivor path metric in Viterbi-type forward error correction decoding. 
     
     
       4. The method of  claim 1  wherein the soft metric is a difference between a best survivor path metric and a second best survivor path metric in Viterbi-type forward error correction decoding. 
     
     
       5. The method of  claim 1  wherein the channel link quality is evaluated by comparing a bit error rate with a threshold. 
     
     
       6. The method of  claim 1  further comprising:
 descrambling the coded bits of the PAN field and the PCS with a TBF-specific scrambling code. 
 
     
     
       7. An apparatus for processing a piggybacked acknowledgement/non-acknowledgement (PAN) field included in a data block to indicate an acknowledgement (ACK) or a non-acknowledgement (NACK) for a particular temporary block flow (TBF), the TBF being a temporal connection between a mobile station and a network to support a uni-directional transfer of data, the apparatus comprising:
 a transceiver configured to receive a data block including coded bits of a PAN field and a PAN check sequence (PCS); 
 a decoder configured to decode the coded bits of the PAN field and the PCS; and 
 a processing unit configured to evaluate a channel link quality based on a soft metric computed during decoding of the coded bits of the PAN field and the PCS, and accept the PAN field and the PCS based on evaluation of the channel link quality. 
 
     
     
       8. The apparatus of  claim 7  wherein the processing unit is configured to evaluate the channel link quality by comparing a soft metric computed during the decoding of the coded bits with a threshold. 
     
     
       9. The apparatus of  claim 7  wherein the soft metric is a best survivor path metric in Viterbi-type forward error correction decoding. 
     
     
       10. The apparatus of  claim 7  wherein the soft metric is a difference between a best survivor path metric and a second best survivor path metric in Viterbi-type forward error correction decoding. 
     
     
       11. The apparatus of  claim 7  wherein the processing unit is configured to evaluate the channel link quality by comparing a bit error rate with a threshold. 
     
     
       12. The apparatus of  claim 7  further comprising:
 a descrambler for descrambling the coded bits of the PAN field and the PCS with a TBF-specific scrambling code.